The L.A. Times music blog

Billed as "the biggest live music event in radio history," the two-day festival, set for the MGM Grand in Las Vegas in September, also features Alicia Keys, Nicki Minaj and Kelly Clarkson.

Though summer has already had its fair share of big-ticket, multiday festivals, Clear Channel is kicking off fall with what it's billing as "the biggest live music event in radio history."

The radio conglomerate on Monday announced the lineup for the inaugural iHeartRadio Music Festival, and the roster for the two-day festival, set for Sept. 23 and 24 at the MGM Grand in Las Vegas, is quite the who’s who among Top 40.

“This is a once-in-a-generation gathering of artists and fans from all over the country for a true, must-see music event,” Ryan Seacrest said in a video statement. “The iHeartRadio Music Festival, like the iHeartRadio digital radio service, will showcase top artists across all genres of music. Listeners from all over America will travel to Las Vegas to celebrate the next generation of iHeartRadio, while seeing the greatest musicians in the world on one stage.”

Seacrest will host the two-day affair, and each of the performances will stream live online, on mobile devices and through select radio station websites. More performers are expected to be added to the bill.

The festival supports the launch of the iHeartRadio app, which allows users streaming access to radio programming.

Pre-sale tickets are available now through Facebook; tickets go on sale to the general public through Ticketmaster on Saturday at 10 a.m. More info can be found on the festival's website.